What I've learned over the years is that people come and people go. It's just something that you learn to appreciate, tbh. Like, yes: you're no longer friends, but also yes: you have these great memories and you get to appreciate how this person effected your life.
It was kind of rude of your friend to tell you straight up that you're not friends anymore. They must be going through a lot of changes in their life, or something. But, the thing with friends is that you usually can find a new one. It won't be tomorrow, and it won't be all at once, but you'll get a new bestie. And they might drift away from you one day, too, but the important thing is the good times you have together.
I'm probably being a bit too dark haha. But that's just life: ubi sunt, more or less.